The replacement of areas of the aorta close to the heart, particularly the so-called “ascending aorta,” is one of the most important specialties of modern heart surgery. A number of vascular prostheses are now available for doing this. The vascular prostheses are usually implanted after removal of the aneurysmatic sections of the ascending aorta and, particularly, after removal of the aortic sinus (natural sinus) while retaining the aortic valves and sections of the arterial wall.
The early vascular prostheses were straight and homogeneous tubular prostheses. The disadvantage of these types of vascular prostheses is that they do not have the additional structures which could replace the functions of the surgically removed aortic sinus in particular. Consequently, they do not conform adequately to the actual anatomical conditions of the ascending aorta.
Tubular vascular prostheses for replacing the ascending aorta are known from U.S. Pat. No. 6,544,285 B1 and WO 01/52776 A1, which have artificial sinuses in the area close to the heart for replacing the aortic sinuses. The artificial sinuses are sewn to the prosthesis. Arched bulges are formed at the end close to the heart of the vascular prosthesis by the sewn-on sinuses. Basically, these vascular prostheses do improve the conformation to the actual anatomical conditions of the ascending aorta, but it is much more difficult to implant them.
EP 0 955 019 A2 concerns tubular vascular prostheses having a generally circumferential bulge in the region of the aortic bulb. Even this prosthesis configuration does not correspond to the actual anatomy of the ascending aorta. WO 2004/021925 A2 describes a tubular vascular prosthesis that has been improved in this respect, whereby the tubes in the region of the ascending aorta have at least two artificial sinuses, which have a greater external dimension than the tubes themselves. Furthermore, U.S. Pat. No. 5,139,515 describes an aortic prosthesis having sinus-like bulges, but does not give any more details on the formation of the bulges. WO 2005/099624 A1 describes a woven aortic sinus prosthesis having a substantially spherical bulb section. A complicated weaving technique is required to produce it.
It could therefore be helpful to provide a vascular prosthesis for replacing the ascending aorta which is easy to produce and which avoids the known disadvantages of the prior art, and which particularly has a configuration which satisfactorily conforms to the natural anatomical conditions of the ascending aorta.